The invention relates to a spinning or twisting spindle having a vertical spindle shaft which is disposed in a spindle bearing housing by means of a bolster and a step bearing. The spindle bearing housing can be fastened to a spindle rail below the step bearing, by means of a holding device which is essentially radially spring-elastically flexible.
In the case of a spindle of the initially mentioned type (German Patent Document DE-AS 11 83 415, FIG. 6), the spindle bearing housing is arranged in an outer housing which surrounds it. The outer housing is extended beyond the area of the step bearing and is provided with transverse slots which are disposed in several planes and form a row of springy ring segments which are connected with one another by means of short webs. As a result, a type of swivel point is to be created around which the housing receiving the spindle bearing housing can be swivelled. In addition, the spindle bearing housing is held in the outer housing in an elastic manner such that it can carry out swivelling or tumbling motions inside the housing.
It is an object of the invention to provide a spinning or twisting spindle of the initially mentioned type by means of which it becomes possible to reduce the running noises.
This object is achieved according to preferred embodiments of the invention in that the holding device contains a pin made of springy materials as an extension of the spindle bearing housing, the cross-section of this pin being smaller than the cross-section of the spindle bearing housing and the pin forming a point of discontinuity.
In this case, the invention is based on the recognition that an essential cause of the running noises rests with the construction of the bolster which normally contains roller bodies. Even if this bolster is manufactured with high precision with respect to its shape and only a small play is permitted, smaller deviations still cannot be avoided. These deviations have the result that the roller bodies and thus also the spindle bearing housing are set to perform vibrations which have the effect of a sound wave. These vibrations are then transmitted by means of a so-called flow of structure-borne sound, to other machine elements which have larger surfaces capable of vibrating and thus result in an increase in the generating of noise. According to the invention, the pin forms a point of discontinuity which must be considered as a throttling point for the flow of the structure-borne sound. Vibrations of the spindle bearing housing are therefore only to a clearly reduced extent transmitted to other machine elements and particularly to the spindle rail. As a result the generating of noise is essentially reduced to the spindle bearing housing.
In a further development of the invention, it is provided that the holding device comprises devices for adjusting the angular position of the spindle. Spindles of this type are normally driven by means of a tangential belt or another belt drive which exercises a load on the spindle in the radial direction. This will result in a deformation in the area of the pin which can be compensated by the devices for the adjusting in such a manner that the spindle loaded by means of the driving belt is largely aligned perpendicularly and, in the case of a ring spindle, particularly in the center with respect to the center of the ring.
In a further development of the invention, it is provided that the pin is manufactured in one piece with the spindle bearing housing. The mounting of the pin will then not result in significantly increased manufacturing expenses because the manufacturing may take place as a machining by means of turning. In an expedient further development, it is provided that a fastening flange and a thread bolt connect to the pin serving as the point of discontinuity. These elements may also be manufactured in a simple manner in one operation in one piece with the spindle bearing housing and the pin.
In a further development of the invention, it is provided that the spindle bearing housing is surrounded by a ring made of a rubber elastic material in the area of the bolster. This ring, which may be mounted either to the spindle bearing housing or to a recess of a spindle rail, is essentially used as a safety device for preventing excessive deviations or deflections of the spindle. Stronger deflections of this type may occur, for example, during the starting of a machine and in the case of the loads occurring during the starting.
In a further development of the invention, it is provided that the spindle bearing housing is surrounded by a shell of sound-absorbing material. As a result, it is also possible to provide a further protection from the sound waves radiating from the spindle bearing housing so that a further noise reduction is obtained. It is advantageous in this case for the shell to be held at the spindle bearing housing in the area of the bolster and to surround the remaining area of the spindle bearing housing at a distance. A shell of this type may be mounted at any time later.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.